two small islands in the Bering Strait, lying about 2 ¹/₂ mi (4 km) apart and separated by the U.S.–Russian boundary, which coincides with the International Date Line. The larger island, Big Diomede (Russian Ostrov Ratmanova 【Ratmanov Island】), has an area of 4 sq mi (10 sq km) and is part of the Chukchi autonomous okrug, in Russia. It has no permanent population but is the site of an important Russian weather station. To the east lies Little Diomede Island, a part of Alaska, inhabited by Chukchi people who are skilled seamen. The islands' first European visitor was the Danish navigator Vitus Jonassen Bering (Bering, Vitus) on Aug. 16 (St. Diomede's Day), 1728. Pop. (1990) Little Diomede Island (Diomede city) 178.